const focus = {
    install (Vue) {
        
        Vue.directive('focus', {
            inserted: function (el, {value}) {
                if (value) {
                    el.focus()
                }
            }
        })


        Vue.directive('loadmore', {
            bind(el, binding) {    
                var p = 0;    
                var t = 0;    
                var down = true; 
                var interval = 300   
                var isActive = true
                debugger
                el.addEventListener('scroll', function() {     
                    if (!isActive) {
                        return
                    } 
                    //判断是否向下滚动      
                    p = this.scrollTop;   
                    if(t < p){        
                        down = true;      
                    }else{        
                        down = false;      
                    }      
                    t = p;      
                    //判断是否到底      
                    const sign = 10;      
                    const scrollDistance = this.scrollHeight - this.scrollTop - this.clientHeight;      
                    if (scrollDistance <= sign && down) {        
                        binding.value()  
                        isActive = false
                        setTimeout(() => {
                            isActive = true
                        }, interval)    
                    }    
                });  
            }
        })
        
    }
}
export default focus
